Electronic devices can have narrow operating voltage and/or current requirements and may not be able to tolerate wide voltage swings or power surges. Existing power supplies often assume a regulated or predictable source of power such as that supplied by the household mains or a battery. In some applications, the power source to a power supply circuit may be unpredictable and may include wide voltage swings and surges. In applications where the power source includes a highly resonant wireless power source, for example, power source characteristics may quickly change due to changes in coupling, positioning of devices and/or movement of devices and extraneous objects resulting in voltage fluctuations and/or surges. Components of existing power supplies, such as switches, diodes, rectifiers, and the like may fail or overheat during the fluctuations and may be unable to provide a reliable output power to the electronic device.